I remember taking a course in statistics many years ago, One of the text books was called, How To Lie With Statistics.
Since than I have taken all polls with a grain of salt.
The only guy I would be willing to believe is Michael Barone. That man is a walkin', talkin encyclopedia.
There's another interesting statistic that's hidden in both polls. Check out the missing voters! In the Barna poll, the number of undecided/undeclared religious voters runs an average of 26%! The Catholic group ran highest with 32% undecided, and the "other than Christianity" ran lowest with 20%.
Now compare that to the Gallup poll, where every group ran about 9 - 10% undecided.